4X2-X-9=0X2-X/4-9/4=0X2-X/4+1/64=9/4+1/64=145/64(X-1/8)2=145/64X=正负(1+根号145)/8
4x²-x=94x²-x+1/16=9+1/16(2x-1/4)²=145/162x-1/4=±√145/4则:x=(1±√145)/8
4x²-x=9 (2x-1/4)^2=9+1/16=145/16 2x-1/4=±√145/4 x1=1/8+√145/8 x2=1/8-√145/8